Provide a cmake utility dune_default_include_directories

CMakeLists.txt

@@ -14,6 +14,7 @@ list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/modules)
 
 #include the dune macros
 include(DuneMacros)
+dune_policy(SET DP0001 NEW)
 
 # start a dune project with information from dune.module
 dune_project()
@@ -21,6 +22,9 @@ dune_project()
 # Create a target for dune-common with a Dune::Common alias
 dune_add_library(dunecommon EXPORT_NAME Common NAMESPACE Dune::)
 
+# set include directories for dunecommon library
+dune_default_include_directories(dunecommon PUBLIC)
+
 # minimal c++ standard required
 target_compile_features(dunecommon PUBLIC cxx_std_17)
 

cmake/modules/DuneDefaultIncludeDirectories.cmake

+# SPDX-FileCopyrightInfo: Copyright © DUNE Project contributors, see file LICENSE.md in module root
+# SPDX-License-Identifier: LicenseRef-GPL-2.0-only-with-DUNE-exception
+
+#[=======================================================================[.rst:
+DuneDefaultIncludeDirectories
+-----------------------------
+
+Add the default include directories to a target.
+
+.. cmake:command:: dune_default_include_directories
+
+  Add the source and build directory the the targets include directories
+  in the build-interface and the corresponding installed include dir in
+  the install-interface.
+
+  .. code-block:: cmake
+
+    dune_default_include_directories(<target> [PRIVATE|PUBLIC|INTERFACE])
+
+#]=======================================================================]
+include_guard(GLOBAL)
+
+function(dune_default_include_directories _target _scope)
+  target_include_directories(${_target} ${_scope}
+    $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}>
+    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}>
+    $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}/include>
+    $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}/include_private>
+    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+endfunction(dune_default_include_directories)
\ No newline at end of file

cmake/modules/DuneMacros.cmake

@@ -35,6 +35,7 @@ enable_language(C) # Enable C to skip CXX bindings for some tests.
 set(THREADS_PREFER_PTHREAD_FLAG TRUE CACHE BOOL "Prefer -pthread compiler and linker flag")
 
 include(DuneAddLibrary)
+include(DuneDefaultIncludeDirectories)
 include(DuneEnableAllPackages)
 include(DuneExecuteProcess)
 include(DuneModuleDependencies)

cmake/modules/DuneProject.cmake

@@ -57,6 +57,9 @@ include(GNUInstallDirs)
 include(Headercheck)
 include(OverloadCompilerFlags)
 
+include(DunePolicy)
+dune_define_policy(DP0001 dune-common 3.0
+  "OLD behavior: Use global include_directories. NEW behavior: Include directories must be set on a module library target and are not set globally anymore.")
 
 # Macro that should be called near the beginning of the top level CMakeLists.txt.
 # Namely it sets up the module, defines basic variables and manages
@@ -163,12 +166,17 @@ macro(dune_project)
   include(CheckCXXFeatures)
 
   # set include path and link path for the current project.
-  include_directories("${PROJECT_BINARY_DIR}")
-  include_directories("${PROJECT_SOURCE_DIR}")
-  include_directories("${CMAKE_CURRENT_BINARY_DIR}")
-  include_directories("${CMAKE_CURRENT_SOURCE_DIR}")
-  include_directories("${CMAKE_CURRENT_BINARY_DIR}/include")
-  include_directories("${CMAKE_CURRENT_BINARY_DIR}/include_private")
+  dune_policy(GET DP0001 _include_policy)
+  if(_include_policy STREQUAL "OLD")
+    include_directories("${PROJECT_BINARY_DIR}")
+    include_directories("${PROJECT_SOURCE_DIR}")
+    include_directories("${CMAKE_CURRENT_BINARY_DIR}")
+    include_directories("${CMAKE_CURRENT_SOURCE_DIR}")
+    include_directories("${CMAKE_CURRENT_BINARY_DIR}/include")
+    include_directories("${CMAKE_CURRENT_BINARY_DIR}/include_private")
+    set(CONFIG_INCLUDE_DIRS "set_and_check(${ProjectName}_INCLUDE_DIRS \"@PACKAGE_CMAKE_INSTALL_INCLUDEDIR@\")")
+  endif()
+  unset(_include_policy)
   add_definitions(-DHAVE_CONFIG_H)
 
   # Create custom target for building the documentation
@@ -288,7 +296,7 @@ set(${ProjectName}_INSTALLED @MODULE_INSTALLED@)
 
 #report other information
 set_and_check(${ProjectName}_PREFIX \"\${PACKAGE_PREFIX_DIR}\")
-set_and_check(${ProjectName}_INCLUDE_DIRS \"@PACKAGE_CMAKE_INSTALL_INCLUDEDIR@\")
+${CONFIG_INCLUDE_DIRS}
 set(${ProjectName}_CMAKE_CONFIG_VERSION \"${DUNE_COMMON_VERSION}\")
 set(${ProjectName}_CXX_FLAGS \"${CMAKE_CXX_FLAGS}\")
 set(${ProjectName}_CXX_FLAGS_DEBUG \"${CMAKE_CXX_FLAGS_DEBUG}\")